<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    var
    <script>
        //es6  ts(java)
        var a = 3;
        var a = 8;

        // let b = 4;
        // let b = 7;
        if(true){
            var m = 8;
            let n = 10;
            {
                let n = 88;
                console.log('n',n);
            }
        }
        // console.log('m',m);
        // console.log('n',n);
    </script>
    <script>
        console.log('=======');
        // C1
        // const c1 = 3;
        // c1 = 7;
        // console.log('c1',c1);
        // cat地址
        const cat = {
            name:"加菲猫",
            age:5
        }
        console.log(cat);
        //new 语法糖
        // cat = {
        //     name:"加菲猫",
        //     age:5
        // }
        //错误
        // console.log(cat);

        cat.age = 100;
        console.log(cat);
    </script>
</body>
</html>